Question

Consider the circuit shown in figure 5 that you used in your lab. Suppose you take another voltmeter and measure the voltage across the power supply (between the and and you find value Vp. The voltage measured by the voltmeter across the resistance Rz is VR: Which of the following is correct

Power Supply
R3
Figure 5
statement? You would always find that Vp is equal to VR regardless of the resistance of the ammeter:
You could find that Vp is less than VR which would indicate that the resistance of the ammeter is not negligible.
You could find that Vp is greater than VR which would indicate that the resistance of the ammeter is not negligible_

Answer 1

When the voltmeter's resistance is comparable to the device being measured, it affects the circuit, resulting in a voltage difference. If the voltage across the power supply is greater than the voltage across the resistance, it indicates that the resistance of the ammeter is not negligible.

Step-by-step explanation:

In order to determine whether the resistance of the ammeter is negligible or not, we need to consider how the voltmeter affects the circuit. When the voltmeter's resistance is much greater than the device being measured, very little current flows through the voltmeter and it does not appreciably affect the circuit. However, if the voltmeter's resistance is comparable to that of the device, then the two in parallel have a smaller resistance, which affects the circuit. In this case, the voltage measured by the voltmeter across the resistance Rz (VR) will not be equal to the voltage across the power supply (Vp). If Vp is greater than VR, it indicates that the resistance of the ammeter is not negligible.